<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="" method="post">
    <p><input type="text" placeholder="用户名" name="username"></p>
    <p><input type="password" placeholder="密码" name="password"></p>
    <p><input type="submit" value="登录"></p>
</form>
</body>
</html>